This project includes the synthesis, reactivity study, and collaborative biological testing of certain derivatives of polycyclic aromatic amine carcinogens and some potential new types of carcinogens which have been selectively designed to provide information concerning: 1) structrual requirements necessary or sufficient for carcinogenic activity at a given organ site, 2) positive identification of some metabolic products arising from the action of the carcinogens on cellular proteins, 3) the structures and perhaps significance of some of the carcinogen-nucleic acid adducts, 4) a unified hypothesis of carcinogenesis which has been proposed.